<template>
  <div style="padding: 10px; margin-bottom: 50px">
      <el-row>
          <el-col :span="8">
              <el-card style="width: 100%; min-height: 300px; color: #333">
                  <div style="padding-bottom: 10px; border-bottom: 1px solid #ccc">在线用户<span
                          style="font-size: 12px">（点击聊天气泡开始聊天）</span></div>
                  <div style="padding: 10px 0" v-for="user in users" :key="user.username">
                      <span>{{ user.username }}</span>
                      <i class="el-icon-chat-dot-round" style="margin-left: 10px; font-size: 16px; cursor: pointer"
                          @click="chatUser = user.username"></i>
                      <span style="font-size: 12px;color: limegreen; margin-left: 5px"
                          v-if="user.username === chatUser">chatting...</span>
                  </div>
              </el-card>
          </el-col>
          <el-col :span="16">
              <div style="width: 800px; margin: 0 auto; background-color: white;
                    border-radius: 5px; box-shadow: 0 0 10px #ccc">
                  <div style="text-align: center; line-height: 50px;">
                      Web聊天室（{{ chatUser }}）
                  </div>
                  <div style="height: 350px; overflow:auto; border-top: 1px solid #ccc" v-html="content"></div>
                  <div style="height: 200px">
                      <textarea v-model="text" style="height: 160px; width: 100%; padding: 20px; border: none; border-top: 1px solid #ccc;
             border-bottom: 1px solid #ccc; outline: none"></textarea>
                      <div style="text-align: right; padding-right: 10px">
                          <el-button type="primary" size="mini" @click="send">发送</el-button>
                      </div>
                  </div>
              </div>
          </el-col>
      </el-row>
  </div>
</template>
<script>
import { mapGetters } from 'vuex'

let socket;
export default {
  name: "UserChat",
  data() {
      return {
          circleUrl: 'https://cube.elemecdn.com/3/7c/3ea6beec64369c2642b92c6726f1epng.png',
          user: {},
          isCollapse: false,
          users: [],
          chatUser: '',
          text: "",
          messages: [],
          content: ''
      }
  },
  created() {
      this.init()
  },
  computed: {
      ...mapGetters('user', ['getUser']) // 添加getters映射
  },
  methods: {
      send() {
          if (!this.chatUser) {
              this.$message({ type: 'warning', message: "请选择聊天对象" })
              return;
          }
          if (!this.text) {
              this.$message({ type: 'warning', message: "请输入内容" })
          } else {
              if (typeof (WebSocket) == "undefined") {
                  console.log("您的浏览器不支持WebSocket");
              } else {
                  console.log("您的浏览器支持WebSocket");
                  // 组装待发送的消息 json
                  // {"from": "zhang", "to": "admin", "text": "聊天文本"}
                  let message = { from: this.user.username, to: this.chatUser, text: this.text }
                  socket.send(JSON.stringify(message));  // 将组装好的json发送给服务端，由服务端进行转发
                  this.messages.push({ user: this.user.username, text: this.text })
                  // 构建消息内容，本人消息
                  this.createContent(null, this.user.username, this.text)
                  this.text = '';
              }
          }
      },
      createContent(remoteUser, nowUser, text) {  // 这个方法是用来将 json的聊天消息数据转换成 html的。
          let html
          // 当前用户消息
          if (nowUser) { // nowUser 表示是否显示当前用户发送的聊天消息，绿色气泡
              html = "<div class=\"el-row\" style=\"padding: 5px 0\">\n" +
                  "  <div class=\"el-col el-col-22\" style=\"text-align: right; padding-right: 10px\">\n" +
                  "    <div class=\"tip left\">" + text + "</div>\n" +
                  "  </div>\n" +
                  "  <div class=\"el-col el-col-2\">\n" +
                  "  <span class=\"el-avatar el-avatar--circle\" style=\"height: 40px; width: 40px; line-height: 40px;\">\n" +
                  "    <img src=\"https://cube.elemecdn.com/3/7c/3ea6beec64369c2642b92c6726f1epng.png\" style=\"object-fit: cover;\">\n" +
                  "  </span>\n" +
                  "  </div>\n" +
                  "</div>";
          } else if (remoteUser) {   // remoteUser表示远程用户聊天消息，蓝色的气泡
              html = "<div class=\"el-row\" style=\"padding: 5px 0\">\n" +
                  "  <div class=\"el-col el-col-2\" style=\"text-align: right\">\n" +
                  "  <span class=\"el-avatar el-avatar--circle\" style=\"height: 40px; width: 40px; line-height: 40px;\">\n" +
                  "    <img src=\"https://cube.elemecdn.com/3/7c/3ea6beec64369c2642b92c6726f1epng.png\" style=\"object-fit: cover;\">\n" +
                  "  </span>\n" +
                  "  </div>\n" +
                  "  <div class=\"el-col el-col-22\" style=\"text-align: left; padding-left: 10px\">\n" +
                  "    <div class=\"tip right\">" + text + "</div>\n" +
                  "  </div>\n" +
                  "</div>";
          }
          console.log(html)
          this.content += html;
      },
      init() {
          this.user = this.getUser;
          let username = this.user.username;
          let _this = this;
          if (typeof (WebSocket) == "undefined") {
              console.log("您的浏览器不支持WebSocket");
          } else {
              console.log("您的浏览器支持WebSocket");
              let socketUrl = "ws://localhost:8080/imserver/" + username;
              if (socket != null) {
                  socket.close();
                  socket = null;
              }
              // 开启一个websocket服务
              socket = new WebSocket(socketUrl);
              //打开事件
              socket.onopen = function () {
                  console.log("websocket已打开");
              };
              //  浏览器端收消息，获得从服务端发送过来的文本消息
              socket.onmessage = function (msg) {
                  console.log("收到数据====" + msg.data)
                  let data = JSON.parse(msg.data)  // 对收到的json数据进行解析， 类似这样的： {"users": [{"username": "zhang"},{ "username": "admin"}]}
                  if (data.users) {  // 获取在线人员信息
                      _this.users = data.users.filter(user => user.username !== username)  // 获取当前连接的所有用户信息，并且排除自身，自己不会出现在自己的聊天列表里
                  } else {
                      // 如果服务器端发送过来的json数据 不包含 users 这个key，那么发送过来的就是聊天文本json数据
                      //  // {"from": "zhang", "text": "hello"}
                      if (data.from === _this.chatUser) {
                          _this.messages.push(data)
                          // 构建消息内容
                          _this.createContent(data.from, null, data.text)
                      }
                  }
              };
              //关闭事件
              socket.onclose = function () {
                  console.log("websocket已关闭");
              };
              //发生了错误事件
              socket.onerror = function () {
                  console.log("websocket发生了错误");
              }
          }
      }
  }
}
</script>
<style>
.tip {
  color: white;
  text-align: center;
  border-radius: 10px;
  font-family: sans-serif;
  padding: 10px;
  width: auto;
  display: inline-block !important;
  display: inline;
}

.right {
  background-color: deepskyblue;
}

.left {
  background-color: forestgreen;
}
</style>